Optical fibers have been widely used for industrial communication systems. In optical devices such as lasers, photodetectors, feedthroughs and sensors, the optical fiber and other device components need to be joined. As a requisite step, the optical fiber needs to be first metalized. There exist several techniques in the prior art for metalization of the optical fibers. A conventional approach is to use a vacuum deposition technique such as sputtering. A metal layer is sputtered onto the optical fiber. The metal used for sputtering deposition includes titanium, platinum and gold. The sputtered metal has relatively good adhesion properties on the optical fiber. However, this approach is not only expensive but also produces a non-uniform coating. It also tends to weaken the optical fiber and puts limitations on the type of polymeric jacket that can be used in the vacuum of the sputtering chamber.
Another technique has been used in the past is electroless deposition of nickel to metalize the glass surface of the optical fiber. A glass surface of the optical fiber is prepared for the electroless deposition of nickel by applying onto the surface a sensitizer which acts to deposit a catalyst for the nickel reduction from an electroless nickel plating solution. U.S. Pat. No. 5,380,559 to Filas et al. discloses an electroless process to deposit nickel and gold onto an optical fiber using aqueous chemistry. The key to the process is a sensitization of the surface of the optical fiber using a dilute aqueous stannous fluoride solution in absence of oxygen. Stannous fluoride solution is prepared by dissolving crystalline SnF.sub.2 in deionized water. Subsequent treatment includes immersion of sensitized optical fiber in a palladium chloride/HCl aqueous solution and commercially available electroless nickel and electroless gold solutions. Although it is possible to obtain reproducible plating of nickel on the surface of the optical fiber according to this approach, it is inconvenient and put a lot of restrictions on the process condition because the majority of process steps need to be performed in absence of oxygen. Thus, a simple and yet reproducible process for the electroless metalization of optical fibers is needed.